Prostate Cancer Patient Characteristics Associated With a Strong Preference to Preserve Sexual Function and Receipt of Active Surveillance
JNCI J Natl Cancer Inst (
Prostate Cancer Patient Characteristics Associated With a Strong Preference to Preserve Sexual Function and Receipt of Active Surveillance
James R. Broughman 0 1
Ramsankar Basak 0 1
Matthew E. Nielsen 0 1
Bryce B. Reeve 0 1
Deborah S. Usinger 0 1
Kiayni C. Spearman 0 1
Paul A. Godley 0 1
Ronald C. Chen 0 1
0 The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions , please
1 Affiliations of authors: Department of Radiation Oncology (JRB , RB, DSU, KCS, RCC) , School of Medicine (JRB, BBR, PAG, RCC), Lineberger Comprehensive Cancer Center (PAG, RCC), Department of Urology (MEN), and Gillings School of Global Public Health (BBR), University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
Background: Men with early-stage prostate cancer have multiple options that have similar oncologic efficacy but vary in terms of their impact on quality of life. In low-risk cancer, active surveillance is the option that best preserves patients' sexual function, but it is unknown if patient preference affects treatment selection. Our objectives were to identify patient characteristics associated with a strong preference to preserve sexual function and to determine whether patient preference and baseline sexual function level are associated with receipt of active surveillance in low-risk cancer. Methods: In this population-based cohort of men with localized prostate cancer, baseline patient-reported sexual function was assessed using a validated instrument. Patients were also asked whether preservation of sexual function was very, somewhat, or not important. Prostate cancer disease characteristics and treatments received were abstracted from medical records. A modified Poisson regression model with robust standard errors was used to compute adjusted risk ratio (aRR) estimates. All statistical tests were two-sided. Results: Among 1194 men, 52.6% indicated a strong preference for preserving sexual function. Older men were less likely to have a strong preference (aRR ¼ 0.98 per year, 95% confidence interval [CI] ¼ 0.97 to 0.99), while men with normal sexual function were more likely (vs poor function, aRR ¼ 1.59, 95% CI ¼ 1.39 to 1.82). Among 568 men with low-risk cancer, there was no clear association between baseline sexual function or strong preference to preserve function with receipt of active surveillance. However, strong preference may differnetially impact those with intermediate baseline function vs poor function (Pinteraction ¼ .02). Conclusions: Treatment choice may not always align with patients' preferences. These findings demonstrate opportunities to improve delivery of patient-centered care in early prostate cancer.
Prostate cancer is the most common nonskin cancer among
men, with more than 180 000 new cases diagnosed each year in
the United States (
). Over 90% of newly diagnosed patients
have localized disease and are potentially curable (
patients often have several treatment options available—which
can include active surveillance, radical prostatectomy, or
radiation therapy—which have been shown to result in similar
survival (4) but different quality of life effects in terms of sexual,
urinary, and bowel function (
). Radical prostatectomy is
associated with worse sexual function and urinary incontinence
compared with active surveillance, external beam radiotherapy
and brachytherapy with worse short-term urinary obstruction
and irritation, and external beam radiotherapy with worse
short-term bowel symptoms (
). Therefore, it is well
recognized that treatment decisions for localized prostate
cancer are preference-sensitive and need to account for each
patient’s goals and priorities (
Specifically, different treatment options can have different
magnitudes of impact on a patient’s sexual function (
For many men diagnosed with localized prostate cancer,
choosing a treatment option that better allows preservation of sexual
function may be prioritized. On the other hand, as the median
age of prostate cancer diagnosis is 66 years (
), some men may
already have clinically significant baseline sexual dysfunction,
and function preservation may not be a high priority. It seems
logical that part of the treatment decision-making process
between the patient and his physicians would be consideration of
his baseline sexual function level and the relative priority he
places on preserving this function. For men with low-risk
prostate cancer that is unlikely to be life threatening, active
surveillance is the best option to preserve sexual function.
In a population-based, sociodemographically diverse,
prospective cohort of newly diagnosed prostate cancer patients,
baseline (pretreatment) sexual function was assessed using a
validated quality of life instrument, and each patient also
indicated whether preserving sexual function was of high priority.
In this study, we sought to examine patient characteristics
(including age, race, marital status, baseline sexual function, and
prostate cancer aggressiveness) associated with a high priority
for preserving sexual function. In addition, in low-risk patients,
we examined whether baseline sexual functional level and
patient preference were associated with receipt of active
surveillance—to empirically assess whether these factors
impacted treatment decisions.
The North Carolina Prostate Cancer Comparative Effectiveness
and Survivorship Study (NC ProCESS) is a population-based
cohort of prostate cancer patients, enrolled prior to treatment and
followed prospectively. This study was approved by the
University of North Carolina institutional review board. Details
of patient identification and enrollment were described
), and all patients provided written informed consent.
Briefly, patients with newly diagnosed prostate cancer were
identified through Rapid Case Ascertainment of the North
Carolina Central Cancer Registry from all North Carolina
counties between 2011 and 2013. Upon identification, the patient
was mailed an introductory letter describing the study. This
was followed by a phone call from the study team; if a patient
agreed to participate, a baseline survey was conducted at the
same time (detailed below). The median time from date of
diagnosis to study enrollment and baseline survey was five weeks
(range ¼ 3.1–18.9 weeks). Patients who had already initiated any
prostate cancer treatment were ineligible. Among all eligible
participants, 57.4% agree to participate and were enrolled.
A baseline/pretreatment survey was conducted prior to
treatment for all enrolled patients. Demographic information was
collected by patient report and included date of birth, race,
marital status, educational attainment, and health insurance.
Baseline sexual function was assessed using the validated
Prostate Cancer Symptom Indices (PCSI) (
The Sexual Dysfunction domain of the PCSI includes five
questions that assess patient erectile function (firmness, difficulty
getting and keeping erections), ejaculation, and orgasm.
Answers to these questions are transformed to an overall scale
score from 0 (no dysfunction) to 100 (maximum dysfunction). In
addition to a numerical score, the PCSI has also previously
validated categorizing patients into three levels of function:
normal, intermediate, or poor (
). As defined by the instrument,
normal function describes a patient with essentially no sexual
dysfunction or distress. Intermediate function describes
patients with abnormal but useful sexual function (
with poor sexual function have no useful function or have had
no sexual activity within the past four weeks.
In addition, patients were asked the question “Preserving
your ability to have sex. Would you say this is. . .” And response
choices were very important, somewhat important, or not
important. For purposes of data analysis, we considered patients
who responded “very important” to have a strong preference for
preserving sexual function, and those who indicated
“somewhat” or “not important” to have a lower preference for
Prostate cancer diagnosis information (prostate-specific
antigen [PSA] level, Gleason score, and clinical stage) and first
course of treatment received within one year of diagnosis were
abstracted from medical records. Only patients with early-stage
(nonmetastatic) prostate cancer were included for analysis.
Patients who pursued initial active surveillance but
subsequently received treatment were counted as “active
surveillance,” as were patients who did not receive any
treatment within one year of diagnosis. Prostate cancer risk group
was categorized using definitions from the National
Comprehensive Cancer Network (NCCN) (
In comparing patient characteristics between groups, P values
were calculated using t tests for continuous variables and the
chi-square test for categorical variables.
One goal of this study was to examine characteristics
associated with patients who indicated a strong preference to
preserve sexual function in their treatment decision-making. We
compared the baseline sexual function scores of patients who
indicated strong preference vs lower preference for preserving
sexual function. In addition, multivariable regression was used
to examine additional factors associated with a strong
preference for sexual function preservation. Covariates examined
included baseline sexual function level, age, marital status, race,
NCCN risk group, and education. Specifically, a modified
Poisson regression model with robust standard errors was used
to compute adjusted risk ratio (aRR) estimates.
Another study goal was to empirically assess whether
patient preference impacted treatment received. Specifically, in
low-risk prostate cancer patients, active surveillance is a
standard option and best preserves sexual function (
we hypothesized that low-risk patients with a strong preference
for preserving function and those with normal baseline sexual
function would be most likely to receive active surveillance.
Stratifying patients into six groups based on baseline sexual
function level (normal, intermediate, poor) and patient
preference to preserve function (strong preference vs lower
preference), we examined whether the use of active surveillance
differed by group. Our hypothesis was formally tested using
multivariable modified Poisson regression analysis, which
Importance of preserving sexual function
Strong preference (n ¼ 628)
Lower preference (n ¼ 566)
*P values were calculated using t tests for continuous variables and the chi-square test for categorical variables. All P values were two-sided. NCCN ¼ National
Comprehensive Cancer Network; VA ¼ Veterans Affairs.
examined whether patient preference and baseline sexual
function level were associated with receipt of active surveillance,
and aRR was reported; a preference*baseline function term
specifically examined whether there is an interaction effect
between these two variables. Other covariates included marital
status, age, and race.
All statistical analysis was performed using SAS version 9.4
(Cary, NC), and a P value of less than .05 was considered
statistically significant. All statistical tests were two-sided.
Patient Characteristics and Preference for Preservation of Sexual Function
This population-based cohort of 1194 patients is
sociodemographically diverse, with 27.9% overall being nonwhite and
32.1% with high school or less education. A total of 628 men
(52.6%) indicated a strong preference for preserving sexual
function, and 566 patients (47.4%) indicated a lower preference
Patients who indicated a strong preference for sexual
function preservation had statistically significantly better baseline
function (sexual dysfunction score, mean ¼ 34.5, SD ¼ 35.4)
than patients who indicated a lower preference for function
preservation (mean ¼ 53.5, SD ¼ 39.5, P < .001) (Table 1). In
addition, examining baseline sexual functional levels in the two
patient groups revealed a more nuanced picture. Among patients
who indicated a strong preference to preserve sexual function,
36.4% had normal baseline function but 34.1% actually had poor
function. Conversely, 20.6% of patients who indicated a lower
preference for function preservation had normal baseline
Multivariable analysis confirmed the finding that poor
baseline sexual function was associated with lower likelihood of
patients indicating a strong preference for function
preservation (normal vs poor sexual function aRR ¼ 1.59, 95% CI ¼ 1.39 to
1.82) (Table 2). Older patients were also less likely to indicate a
strong preference to preserve sexual function (aRR ¼ 0.98 per
year, P < .001), as were white patients (aRR ¼ 0.68 to 0.86, P <
.001) and men with high-risk prostate cancer (compared with
low-risk prostate cancer; aRR ¼ 0.71 to 1.00, P ¼ .06). Results
specifically for the low-risk patient subgroup were similar
(Supplementary Tables 1 and 2, available online). Sensitivity
analysis recategorizing patients as “very important” and
“somewhat important” vs “not important” also showed age and
baseline sexual function to be statistically significantly
associated with a stronger preference to preserve function
(Supplementary Tables 3 and 4, available online).
Table 3 summarizes the treatment patterns of 568 patients with
low-risk prostate cancer, stratified by baseline sexual function
level and preference for function preservation. Overall, 43.4% of
low-risk patients received active surveillance. However, we
found no evidence to support our hypothesis of a higher use of
active surveillance in patients with a strong preference to
preserve their sexual function. Among patients with normal
baseline sexual function and a strong preference to preserve this
function, 39.2% received active surveillance; the proportion of
patients who received active surveillance was actually higher
for patients who had normal baseline sexual function but
indicated lower preference to preserve function (49.2%). A similar
finding was seen for patients with poor baseline sexual
function, where again a numerically higher proportion of patients
who indicated a lower preference to preserve sexual function
received active surveillance.
We formally tested our hypothesis using multivariable
analysis, examining factors associated with active surveillance in
low-risk patients (Table 4). Older patients were statistically
significantly more likely to undergo active surveillance (aRR ¼ 1.02
to 1.06 per year, P < .001). Interaction terms examined whether
patient preference differentially impacted patients with
different baseline sexual function levels in their “risk” of receiving
active surveillance. Results suggest that patients with a strong
preference to preserve sexual function are more likely to receive
active surveillance if they have intermediate baseline function
than poor baseline function (Pinteraction ¼ .02). However,
preference to preserve sexual function did not differentially impact
patients with baseline normal vs those with poor function.
In this population-based and diverse cohort of men with
localized prostate cancer, we report several notable findings that
add to the published literature. First, more than half of patients
with newly diagnosed prostate cancer had a strong preference
to preserve sexual function. Second, not surprisingly, younger
patients and those with better baseline sexual function were
more likely to indicate a strong preference for preserving sexual
function. Third, while 43% of low-risk patients received active
surveillance, there was not a clear pattern of patient’s baseline
function or preference for sexual function preservation being
associated with receipt of active surveillance. To the best of our
knowledge, this study is the first to assess whether patient
preference for sexual function preservation matched treatment
received in a large, population-based and diverse cohort of
prostate cancer patients. Prior studies (
) along with ours
provide insights into the prostate cancer treatment-making
Prostate cancer is unique in that many patients with
localized disease have multiple options that have similar
oncologic efficacy but differ in terms of their impact on quality of life
). Thus, decision-making for men with early prostate
cancer is a preference-sensitive process and should take into
account a patient’s priorities. For low-risk patients, active
surveillance results in similar overall survival compared with
radiation and surgery and better preserves sexual function
). In light of this, physicians should inform their low-risk
patients that active surveillance would best meet their
preference for preserving sexual function without compromising life
expectancy. However, it is unknown whether patient preference
is elicited by their physicians or taken into account in final
treatment selection. With this background, there are several
findings that warrant further discussion.
First, while we found that better baseline sexual function
was associated with a higher likelihood of men indicating a
strong preference for function preservation, there are important
exceptions. As Table 1 detailed, one-third of men with normal
baseline sexual function indicated a lower preference for
functional preservation, while 40% of men with poor baseline
function indicated a strong preference. This finding suggests that
simply ascertaining a patient’s baseline sexual function level is
insufficient for determining patient treatment goals because
physicians cannot assume that patients with good sexual
function will always place a high priority on preserving this
function. To allow patients to make an informed decision on
treatment, physicians need to directly ask patients about their
priorities during the decision-making process, including
preferences for sexual function, other quality-of-life impacts (eg,
urinary function), and aggressiveness of cancer treatment. Our
multivariable analysis showed that additional factors
associated with patient preference included patient age and cancer
This study also showed a disconnect between patients’
preference for sexual function preservation and treatment received.
One possible explanation is that physicians may not routinely
elicit patient preferences in making treatment
). Prior studies have shown that prostate cancer
treatment decisions are associated with physician specialty
*ADT ¼ androgen deprivation therapy; AS ¼ active surveillance; NCCN ¼ National Comprehensive Cancer Network; RP ¼ radical prostatectomy; RT ¼ radiotherapy
(includes external beam radiotherapy and brachytherapy).
), and patients who are younger and healthier are more
likely to receive surgery, while older patients more likely to
receive radiotherapy or no treatment. Our findings are consistent
with this and showed that older age was statistically
significantly associated with active surveillance. Whereas age is a
factor that is relatively easy to ascertain during a clinic visit,
thoroughly assessing patients’ baseline sexual function level
and preferences is more time consuming, and there may also be
other cultural barriers to accurately attaining this information
in the clinical setting. The development and use of decision aids
in prostate cancer can help systematically clarify patient
priorities as well as educate patients about treatments that align with
their goals. Several analyses found that decision aids increase
patient knowledge and involvement throughout the
decisionmaking process (33), thus facilitating the delivery of
highquality, patient-centered care. Indeed, patient knowledge about
active surveillance and being fully informed about expectations
are important factors in patient treatment selection (
This study has several strengths and potential limitations. A
strength is the population-based design of modern patients,
which yielded a cohort that is sociodemographically diverse
and more representative than institutional reports. However,
this study was conducted in one East Coast state and may not
be representative of other states or regions, and the 57%
response rate in this study could further limit the generalizability
of results. This study is also unique in assessing
patientreported sexual function prior to treatment, as well as patients’
preference to preserve this function. We are unware of other
large population-based cohorts that contain this information.
However, the latter question was created specifically for this
study, as no validated assessment was available in the
published literature. Furthermore we did not quantify patients’
preferences or their understanding of their preferences
directly—and therefore a definitive conclusion about lack of
congurency in patient preferences with treatment selection
cannot be made. It is also possible that the expressed preference
for maintaining sexual function captured in this study could
reflect physician-patient interaction about treatment options and
consequences. Another potential limitation is that while a
patient may have indicated a strong preference to preserve sexual
function, he may have an even stronger desire for aggressive
treatment or have anxiety related to active surveillance, and we
did not capture the latter information in this study. However,
low-risk prostate cancer is unlikely to be life threatening. For
patients with these early diagnoses who express concurrent
preferences regarding maximizing survival and preserving
sexual function, and if indeed these preferences were ascertained
by their physicians, informed decision-making should include
clarification that choosing active surviellance would be
concordant with patient preferences without compromising survival
outcomes. Finally, this study did not survey physicians, so we
assessed the patients’ treatment selection but were unable to
directly make conclusions about physician recommendations.
The physician plays an important role in treatment selection,
and recommendations vary considerably by specialty (
Furthermore, certain specialties may be more or less attentive
to the preferences of their patients for the preservation of
In this population-based cohort of 1194 men with newly
diagnosed localized prostate cancer, more than half (52.6%)
indicated a strong preference to preserve sexual function in their
treatment decision-making process. However, among men with
a low-risk diagnosis, there was no clear association between
patient preference or baseline sexual function level with receipt of
active surveillance. Although many men with low-risk disease
report that preserving sexual function is a high priority, many
do not receive active surveillance, which is the treatment most
aligned with this preference. These findings call for improved
efforts for delivering high-quality, patient-centered care in this
This study was funded by a Patient-Centered Outcomes
Research Institute (PCORI) contract CER-1310-06453 and a
contract from the Agency for Healthcare Research and
Quality (HHSA290-2005-0040-I-TO6) to PI Ronald Chen.
The sponsors were not involved with the collection,
management, analysis, or interpretation of the data; preparation,
review, or approval of the manuscript; or the decision to submit
the manuscript for publication.
There are no conflicts of interest related to this study. Dr.
Chen reports receiving grants and personal fees from Accuray
and personal fees from Astellas and Medivation. Dr. Nielsen
reports receiving grants from the National Institutes of Health,
the American Cancer Society, and personal fees from Urology
Care Foundation and Astellas, the American College of
Physicians, and Grand Rounds.
1. Siegel RL , Miller KD , Jemal A . Cancer statistics, 2016 . CA Cancer J Clin. 2016 ; 66 ( 1 ): 7 - 30 .
2. Miller KD , Siegel RL , Lin CC , et al. Cancer treatment and survivorship statistics , 2016 . CA Cancer J Clin. 2016 ; 66 ( 4 ): 271 - 289 .
3. DeSantis CE , Lin CC , Mariotto AB , et al. Cancer treatment and survivorship statistics , 2014 . CA Cancer J Clin. 2014 ; 64 ( 4 ): 252 - 271 .
4. Hamdy FC , Donovan JL , Lane JA , et al. 10 -year outcomes after monitoring, surgery, or radiotherapy for localized prostate cancer . N Engl J Med . 2016 ; 375 ( 15 ): 1415 - 1424 .
5. Talcott JA , Manola J , Clark JA , et al. Time course and predictors of symptoms after primary prostate cancer therapy . J Clin Oncol . 2003 ; 21 ( 21 ): 3979 - 3986 .
6. Talcott JA , Clark JA , Manola J , et al. Bringing prostate cancer quality of life research back to the bedside: Translating numbers into a format that patients can understand . J Urol . 2006 ; 176 ( 4 ): 1558 - 1564 .
7. Litwin MS , Hays RD , Fink A , et al. Quality-of-life outcomes in men treated for localized prostate cancer . JAMA . 1995 ; 273 ( 2 ): 129 - 135 .
8. Litwin MS , Pasta DJ , Yu J , et al. Urinary function and bother after radical prostatectomy or radiation for prostate cancer: A longitudinal, multivariate quality of life analysis from the Cancer of the Prostate Strategic Urologic Research Endeavor . J Urol . 2000 ; 164 ( 6 ): 1973 - 1977 .
9. Potosky AL , Legler J , Albertsen PC , et al. Health outcomes after prostatectomy or radiotherapy for prostate cancer: Results from the Prostate Cancer Outcomes Study . J Natl Cancer Inst . 2000 ; 92 ( 19 ): 1582 - 1592 .
10. Stanford JL , Feng Z , Hamilton AS , et al. Urinary and sexual function after radical prostatectomy for clinically localized prostate cancer: The Prostate Cancer Outcomes Study . JAMA . 2000 ; 283 ( 3 ): 354 - 360 .
11. Fowler FJ , Barry MJ , Lu-Yao G , et al. Effect of radical prostatectomy for prostate cancer on patient quality of life: Results from a Medicare survey . Urology . 1995 ; 45 ( 6 ): 1007 - 1015 .
12. Fowler F , Barry MJ , Lu-Yao G , et al. Outcomes of external-beam radiation therapy for prostate cancer: A study of Medicare beneficiaries in three surveillance, epidemiology, and end results areas . J Clin Oncol . 1996 ; 14 ( 8 ): 2258 - 2265 .
13. Donovan JL , Hamdy FC , Lane JA , et al. Patient-reported outcomes after monitoring, surgery, or radiotherapy for prostate cancer . N Engl J Med . 2016 ; 375 ( 15 ): 1425 - 1437 .
14. Sanda MG , Dunn RL , Michalski J , et al. Quality of life and satisfaction with outcome among prostate-cancer survivors . N Engl J Med . 2008 ; 358 ( 12 ): 1250 - 1261 .
15. Holmes-Rovner M , Montgomery JS , Rovner DR , et al. Informed decision making assessment of the quality of physician communication about prostate cancer diagnosis and treatment . Med Decis Making . 2015 ; 35 ( 8 ): 999 - 1009 .
16. Aning J , Wassersug R , Goldenberg S. Patient preference and the impact of decision-making aids on prostate cancer treatment choices and postintervention regret . Curr Oncol . 2012 ; 19 ( suppl 3 ): S37 .
17. Chen RC , Clark JA , Talcott JA . Individualizing quality-of-life outcomes reporting: How localized prostate cancer treatments affect patients with different levels of baseline urinary, bowel, and sexual function . J Clin Oncol . 2009 ; 27 ( 24 ): 3916 - 3922 .
18. Chen RC , Carpenter WR , Kim M , et al. Design of the North Carolina Prostate Cancer Comparative Effectiveness and Survivorship Study (NC ProCESS) . J Comp Eff Res . 2015 ; 4 ( 1 ): 3 - 9 .
19. Clark JA , Bokhour BG , Inui TS , et al. Measuring patients' perceptions of the outcomes of treatment for early prostate cancer . Med Care . 2003 ; 41 ( 8 ): 923 - 936 .
20. Clark JA , Talcott JA . Symptom indexes to assess outcomes of treatment for early prostate cancer . Med Care . 2001 ; 39 ( 10 ): 1118 - 1130 .
21. Nguyen PL , Chen RC , Hoffman KE , et al. Rectal dose-volume histogram parameters are associated with long-term patient-reported gastrointestinal quality of life after conventional and high-dose radiation for prostate cancer: A subgroup analysis of a randomized trial . Int J Radiat Oncol Biol Phys . 2010 ; 78 ( 4 ): 1081 - 1085 .
22. Mohler JL , Armstrong AJ , Bahnson RR , et al. Prostate cancer, version 1 . 2016 . J Natl Compr Canc Netw . 2016 ; 14 ( 1 ): 19 - 30 .
23. Chen RC , Rumble RB , Loblaw DA , et al. Active surveillance for the management of localized prostate cancer (Cancer Care Ontario guideline): American Society of Clinical Oncology clinical practice guideline endorsement . J Clin Oncol . 2016 ; 34 ( 18 ): 2182 - 2190 .
24. Taylor KL , Hoffman RM , Davis KM , et al. Treatment preferences for active surveillance versus active treatment among men with low-risk prostate cancer . Cancer Epidemiol Prev Biomarkers . 2016 ; 25 ( 8 ): 1240 - 1250 .
25. Anandadas CN , Clarke NW , Davidson SE , et al. Early prostate cancer-which treatment do men prefer and why? BJU Int . 2011 ; 107 ( 11 ): 1762 - 1768 .
26. Sidana A , Hernandez DJ , Feng Z , et al. Treatment decision-making for localized prostate cancer: What younger men choose and why . Prostate . 2012 ; 72 ( 1 ): 58 - 64 .
27. Davison BJ , Breckon E . Factors influencing treatment decision making and information preferences of prostate cancer patients on active surveillance . Patient Educ Couns . 2012 ; 87 ( 3 ): 369 - 374 .
28. Elstein AS , Chapman GB , Chmiel JS , et al. Agreement between prostate cancer patients and their clinicians about utilities and attribute importance . Health Expect . 2004 ; 7 ( 2 ): 115 - 125 .
29. Elstein AS , Chapman GB , Knight SJ . Patients' values and clinical substituted judgments: The case of localized prostate cancer . Health Psychol . 2005 ; 24 ( 4S ): S85 .
30. Stalmeier PF , van Tol-Geerdink JJ , van Lin EN , et al. Doctors' and patients' preferences for participation and treatment in curative prostate cancer radiotherapy . J Clin Oncol . 2007 ; 25 ( 21 ): 3096 - 3100 .
31. Sommers BD , Beard CJ , D'Amico AV , et al. Predictors of patient preferences and treatment choices for localized prostate cancer . Cancer . 2008 ; 113 ( 8 ): 2058 - 2067 .
32. Fowler FJ , Jr., McNaughton Collins M , Albertsen PC , et al. Comparison of recommendations by urologists and radiation oncologists for treatment of clinically localized prostate cancer . JAMA . 2000 ; 283 ( 24 ): 3217 - 3222 .
33. Lin GA , Aaronson DS , Knight SJ , et al. Patient decision aids for prostate cancer treatment: A systematic review of the literature . CA Cancer J Clin . 2009 ; 59 ( 6 ): 379 - 390 .
34. Fagerlin A , Rovner D , Stableford S , et al. Patient education materials about the treatment of early-stage prostate cancer: A critical review . Ann Intern Med . 2004 ; 140 ( 9 ): 721 - 728 .